-Option <ScopedItemOptions>
Changes the value of the Options property of the variable. Valid values are:

-- None: Sets no options. ("None" is the default.)

-- ReadOnly: The properties of the variable cannot be changed, except by using the Force parameter. You can use Remove-Variable to delete the variable.

-- Constant: The variable cannot be deleted and its properties cannot be changed. "Constant" is available only when you are creating an alias. You cannot change the option of an existing variable to "Constant".

-- Private: The variable is available only within the scope specified by the Scope parameter. It is inherited by child scopes.

-- AllScope: The variable is copied to any new scopes that are created.

To see the Options property of the variables, type "get-variable| format-table -property name, options -autosize".

-Scope <string>
Determines the scope of the variable. Valid values are "Global", "Local", or "Script", or a number relative to the current scope (0 through the number of scopes, where 0 is the current scope and 1 is its parent). "Local" is the default. For more information, see about_Scopes.

-Visibility <SessionStateEntryVisibility>
Determines whether the variable is visible outside of the session in which it was created. This parameter is designed for use in scripts and commands that will be delivered to other users.

Valid values are:

-- Public: The variable is visible. ("Public" is the default.)
-- Private: The variable is not visible.

When a variable is private, it does not appear in lists of variables, such as those returned by Get-Variable, or in displays of the Variable: drive. Commands to read or change the value of a private variable return an error. However, the user can run commands that use a private variable if the commands were written in the session in which the variable was defined.

# INPUTS
System.Object
You can pipe an object that represents the value of the variable to Set-Variable.

# OUTPUTS
None or System.Management.Automation.PSVariable
When you use the PassThru parameter, Set-Variable generates a System.Management.Automation.PSVariable object representing the new or changed variable. Otherwise, this cmdlet does not generate any output.

# NOTES

# EXAMPLE 1

C:\PS>set-variable -name desc -value "A description"

C:\PS>get-variable -name desc

# Description
-----------
These commands set the value of the "desc" variable to "A description", and then get the value of the variable.

# Description
-----------
This command creates a global, read-only variable that contains all processes on the system, and then it displays all properties of the variable.

The command uses the Set-Variable cmdlet to create the variable. It uses the PassThru parameter to create an object representing the new variable, and it uses the pipeline operator (|) to pass the object to the Format-List cmdlet. It uses the Property parameter of Format-List with a value of all (*) to display all properties of the newly created variable.

The value, "(Get-Process)", is enclosed in parentheses to ensure that it is executed before being stored in the variable. Otherwise, the variable contains the words "Get-Process".

C:\PS> $counter
"Cannot access the variable '$counter' because it is a private variable"

C:\PS> .\use-counter.ps1
Commands completed successfully.

# Description
-----------
This command shows how to change the visibility of a variable to "Private". This variable can be read and changed by scripts with the required permissions, but it is not visible to the user.

The sample output shows the difference in the behavior of public and private variables.